將對象添加到數組對象不適用於android

我是Android的全新體驗。任何人都可以幫我解決我的問題嗎？我想創造一個與牛鬥牛（這是棋盤遊戲）的遊戲。我有一個類Piece可以setType爲Tiger或Cow，我想創建一個如下所示的這個類的數組。將對象添加到數組對象不適用於android

*注：片延伸的ImageView

Piece[] tigers = new Piece[4]; 
for(int i = 0; i < tigers.length; i++) { 
    tigers[i] = new Piece(context); 
    tigers[i].setType(R.drawable.tiger); 
}

下面是我的作品類：

package com.camitss.klasikou; 

import android.content.Context; 
import android.util.Log; 
import android.widget.ImageView; 

public class Piece extends ImageView{ 
    private int type; 

    public Piece(Context context){ 
     super(context); 
     super.setScaleType(ImageView.ScaleType.CENTER_CROP); 
     super.setPadding(4, 4, 4, 4); 
    } 

    public int getType() { 
     return this.type; 
    } 

    public void setType(int type) { 
     this.type = type; 
    } 
}

這裏是我的MainActivity.java

package com.camitss.klasikou; 
import com.camitss.klasikou.R; 
import android.app.Activity; 
import android.content.Context; 
import android.os.Bundle; 
import android.view.Gravity; 
import android.view.Menu; 
import android.view.View; 
import android.view.View.OnClickListener; 
import android.view.Window; 
import android.view.WindowManager; 
import android.widget.GridView; 
import android.widget.LinearLayout; 
import android.widget.RelativeLayout; 

public class MainActivity extends Activity implements OnClickListener{ 

private LinearLayout llNewGame; 
private LinearLayout llInstruction; 
private LinearLayout llOption; 
private LinearLayout llAbout; 
private LinearLayout llCow; 
private LinearLayout llTiger; 


private RelativeLayout p_new_game; 
private RelativeLayout p_instruction; 
private GridView p_fighting; 
public static ImageAdapter imgAdt; 
Context context; 

@Override 
protected void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 

    requestWindowFeature(Window.FEATURE_NO_TITLE); 
    this.getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, 
      WindowManager.LayoutParams.FLAG_FULLSCREEN); 
    setContentView(R.layout.activity_main); 

    llNewGame = (LinearLayout) findViewById(R.id.l_new_game); 
    llNewGame.setOnClickListener(this); 

    llInstruction = (LinearLayout) findViewById(R.id.l_instruction); 
    llInstruction.setOnClickListener(this); 

    llOption = (LinearLayout) findViewById(R.id.l_option); 
    llOption.setOnClickListener(this); 

    llAbout = (LinearLayout) findViewById(R.id.l_about); 
    llAbout.setOnClickListener(this); 

    llCow = (LinearLayout) findViewById(R.id.l_cow); 
    llCow.setOnClickListener(this); 

    llTiger = (LinearLayout) findViewById(R.id.l_tiger); 
    llTiger.setOnClickListener(this); 


    p_new_game = (RelativeLayout) findViewById(R.id.page_new_game); 
    p_instruction = (RelativeLayout) findViewById(R.id.page_instruction); 
    p_fighting = (GridView) findViewById(R.id.page_fighting); 

    imgAdt = new ImageAdapter(this); 

    boardInit(); 

    p_fighting.setAdapter(imgAdt); 
    p_fighting.setGravity(Gravity.CENTER); 
} 

private void llOff(LinearLayout llNewGame, LinearLayout llInstruction, 
     LinearLayout llOption, LinearLayout llAbout) { 
    llNewGame.setBackgroundResource(R.drawable.menu_newgame); 
    llInstruction.setBackgroundResource(R.drawable.menu_instructions); 
    llOption.setBackgroundResource(R.drawable.menu_options); 
    llAbout.setBackgroundResource(R.drawable.menu_about); 
} 

private void wrapInvisible(RelativeLayout p_new_game, 
     RelativeLayout p_instruction) { 
    p_new_game.setVisibility(View.GONE); 
    p_instruction.setVisibility(View.GONE); 
} 

@Override 
public boolean onCreateOptionsMenu(Menu menu) { 
    // Inflate the menu; this adds items to the action bar if it is present. 
    getMenuInflater().inflate(R.menu.main, menu); 
    return true; 
} 

@Override 
public void onClick(View v) { 
    // TODO Auto-generated method stub 
    if (v.getId() == R.id.page_fighting) { 

    } 
    if (v.getId() == R.id.l_cow) { 
     p_new_game.setVisibility(View.GONE); 
     p_fighting.setVisibility(View.VISIBLE); 

    } 
    if (v.getId() == R.id.l_tiger) { 
     p_new_game.setVisibility(View.GONE); 
     p_fighting.setVisibility(View.VISIBLE); 
    } 
    if (v.getId() == R.id.l_new_game) { 
     llOff(llNewGame, llInstruction, llOption, llAbout); 
     wrapInvisible(p_new_game, p_instruction); 
     llNewGame.setBackgroundResource(R.drawable.menu_newgame_on); 
     p_new_game.setVisibility(View.VISIBLE); 
    } 
    if (v.getId() == R.id.l_instruction) { 
     llOff(llNewGame, llInstruction, llOption, llAbout); 
     wrapInvisible(p_new_game, p_instruction); 

     llInstruction.setBackgroundResource(R.drawable.menu_instructions_on); 
     p_instruction.setVisibility(View.VISIBLE); 
    } 
    if (v.getId() == R.id.l_option) { 
     llOff(llNewGame, llInstruction, llOption, llAbout); 
     llOption.setBackgroundResource(R.drawable.menu_options_on); 
    } 
    if (v.getId() == R.id.l_about) { 
     llOff(llNewGame, llInstruction, llOption, llAbout); 
     llAbout.setBackgroundResource(R.drawable.menu_about_on); 
    } 
} 

public void boardInit(){ 
    Piece[] tigers = new Piece[4]; 
    for(int i = 0; i < tigers.length; i++) { 
     tigers[i] = new Piece(context); 
     tigers[i].setType(R.drawable.tiger); 
    } 
} 
}

這裏是我的ImageAdapter.java

package com.camitss.klasikou; 

import android.content.Context; 
import android.database.DataSetObserver; 
import android.view.View; 
import android.view.ViewGroup; 
import android.widget.GridView; 
import android.widget.ImageView; 
import android.widget.ListAdapter; 

public class ImageAdapter implements ListAdapter { 
private Context mContext; 
public Integer[] board = {0,0,0,0, 0,0,0,0, 0,0,0,0, 0,0,0,0}; 

public ImageAdapter(Context c) { 
    mContext = c; 
} 

public void setObjectToBoard(int type, int position) { 
    board[position] = type; 
} 

@Override 
public int getCount() { 
    // TODO Auto-generated method stub 
    return this.board.length; 
} 

@Override 
public Object getItem(int position) { 
    // TODO Auto-generated method stub 
    return this.board[position]; 
//  return null; 
} 

@Override 
public long getItemId(int position) { 
    // TODO Auto-generated method stub 
    return 0; 
} 

@Override 
public int getItemViewType(int position) { 
    // TODO Auto-generated method stub 
    return 0; 
} 

@Override 
public View getView(int position, View convertView, ViewGroup parent) { 
    ImageView imageView; 

    if (convertView == null) { // if it's not recycled, initialize some attributes 
     imageView = new ImageView(mContext); 
     imageView.setLayoutParams(new GridView.LayoutParams(57, 58)); 
    } else { 
     imageView = (ImageView) convertView; 
    } 

    imageView.setImageResource(board[position]); 
    return imageView; 
} 

@Override 
public int getViewTypeCount() { 
    // TODO Auto-generated method stub 
    return 1; 
} 

@Override 
public boolean hasStableIds() { 
    // TODO Auto-generated method stub 
    return false; 
} 

@Override 
public boolean isEmpty() { 
    // TODO Auto-generated method stub 
    return false; 
} 

@Override 
public void registerDataSetObserver(DataSetObserver observer) { 
    // TODO Auto-generated method stub 

} 

@Override 
public void unregisterDataSetObserver(DataSetObserver observer) { 
    // TODO Auto-generated method stub 

} 

@Override 
public boolean areAllItemsEnabled() { 
    // TODO Auto-generated method stub 
    return false; 
} 

@Override 
public boolean isEnabled(int position) { 
    // TODO Auto-generated method stub 
    return false; 
} 

}

問題是無法將新對象添加到該數組。這有什麼問題，應該怎麼做？

錯誤：

03-12 10:36:17.376: E/AndroidRuntime(1331): FATAL EXCEPTION: main 
03-12 10:36:17.376: E/AndroidRuntime(1331): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.camitss.klasikou/com.camitss.klasikou.MainActivity}: java.lang.NullPointerException 
03-12 10:36:17.376: E/AndroidRuntime(1331):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1955) 
03-12 10:36:17.376: E/AndroidRuntime(1331):  at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1980) 
03-12 10:36:17.376: E/AndroidRuntime(1331):  at android.app.ActivityThread.access$600(ActivityThread.java:122) 
03-12 10:36:17.376: E/AndroidRuntime(1331):  at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1146) 
03-12 10:36:17.376: E/AndroidRuntime(1331):  at android.os.Handler.dispatchMessage(Handler.java:99) 
03-12 10:36:17.376: E/AndroidRuntime(1331):  at android.os.Looper.loop(Looper.java:137) 
03-12 10:36:17.376: E/AndroidRuntime(1331):  at android.app.ActivityThread.main(ActivityThread.java:4340) 
03-12 10:36:17.376: E/AndroidRuntime(1331):  at java.lang.reflect.Method.invokeNative(Native Method) 
03-12 10:36:17.376: E/AndroidRuntime(1331):  at java.lang.reflect.Method.invoke(Method.java:511) 
03-12 10:36:17.376: E/AndroidRuntime(1331):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:784) 
03-12 10:36:17.376: E/AndroidRuntime(1331):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:551) 
03-12 10:36:17.376: E/AndroidRuntime(1331):  at dalvik.system.NativeStart.main(Native Method) 
03-12 10:36:17.376: E/AndroidRuntime(1331): Caused by: java.lang.NullPointerException 
03-12 10:36:17.376: E/AndroidRuntime(1331):  at android.view.ViewConfiguration.get(ViewConfiguration.java:314) 
03-12 10:36:17.376: E/AndroidRuntime(1331):  at android.view.View.<init>(View.java:2693) 
03-12 10:36:17.376: E/AndroidRuntime(1331):  at android.widget.ImageView.<init>(ImageView.java:104) 
03-12 10:36:17.376: E/AndroidRuntime(1331):  at com.camitss.klasikou.Piece.<init>(Piece.java:9) 
03-12 10:36:17.376: E/AndroidRuntime(1331):  at com.camitss.klasikou.MainActivity.boardInit(MainActivity.java:134) 
03-12 10:36:17.376: E/AndroidRuntime(1331):  at com.camitss.klasikou.MainActivity.onCreate(MainActivity.java:66) 
03-12 10:36:17.376: E/AndroidRuntime(1331):  at android.app.Activity.performCreate(Activity.java:4465) 
03-12 10:36:17.376: E/AndroidRuntime(1331):  at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1049) 
03-12 10:36:17.376: E/AndroidRuntime(1331):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1919) 
03-12 10:36:17.376: E/AndroidRuntime(1331):  ... 11 more

來源

2013-03-12 Fiemhong

plz還發布stackTrace問題 – 2013-03-12 02:23:12

Piece.java的第10行在哪裏？ – 2013-03-12 02:44:43

仔細檢查每個循環是否使用了正確的數組長度。 – 2013-03-12 02:46:46

你忘了給context非null參考，並自Context終於被投入使用你的Piece班的超級班，NPE在那裏一路拋出。既然你在活動工作改變你的代碼，因此它是採用this關鍵字來代替：

public void boardInit(){ 
    Piece[] tigers = new Piece[4]; 
    for(int i = 0; i < tigers.length; i++) { 
     tigers[i] = new Piece(this); 
     tigers[i].setType(R.drawable.tiger); 
    }

或者如果你使用context真正熱衷，給它一個值調用super.onCreate()後：

@Override 
protected void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    context = this; //add this line

來源

2013-03-12 03:39:26

非常感謝你，A-C和你們所有人都試圖幫助解決我的問題。我現在明白了。 :) :) – Fiemhong 2013-03-12 04:06:54

而不是Piece.length在你的循環應該是tigers.length()和cows.length()

來源

2013-03-12 02:23:58

對不起，我錯了，因爲我不是副本。 – Fiemhong 2013-03-12 02:57:21

將對象添加到數組對象不適用於android

回答

相關問題